Sealing means for a hair clipper



E. C- RANGUS SEALING MEANS FOR A HAIR CLIPPER Filed Aug. 20, 1963 INVEN TOR.

w 9% my m m 5% United States Patent 3,266,143 SEALING MEANS FOR A HAIR CLIPPER Ernest C. Rangus, Lombard, 111., assignor to Supreme Products Corporation, Chicago, Ill. Filed Aug. 20, 1963, Ser. No. 303,333 3 Claims. (Cl. 30224) This invention relates to means to preclude hair clippings and other foreign matter from entering the casing of a hair clipper or like shearing instrnmentality.

As exemplificative of one environment in which the invention may be embodied, this application will make reference to a reciprocating hair clipper of a common type in which the driving mechanism is an electric motor including an armature oscillating in accordance with alternating current applied to a coil. The armature is mounted as a cantilever and the free end is engaged with a reciprocable, toothed, cutting blade coactive with a toothed fixed blade. The mechanism, except for the two blades, is enclosed in a housing. However, in order to permit unobstructed reciprocation of the movable blade some clearance necessarily exists between such blade and the adjacent end of the casing. Accordingly, when the clipper is in use it is inevitable that clippings and perhaps other foreign matter will enter the clearance space and, hence, the interior of the casing and, if provision is not made to preclude such entry, the working parts are adversely affected. For example, the gap between the armature and pole piece of the driving coil may be affected, with consequent interference with the behaviour of the electromagnetic system. Similarly, the on-Ofi? switch may become insulated and operation thereof adversely affected. Moreover, in the interest of cleanliness within the casing generally it is desirable to seal the same against entry of foreign matter.

It has been known to close the aforesaid clearance space by the use of a brush supported on the casing or flexible extensions of the walls of the casing which, in either case, bear frictionally on the rear face of the movable blade. H-owever, such expedients not only wear rapidly but present additional load on the motor.

The principal object of the present invention is to provide sealing means for the purpose stated in which rubbing friction on the sealing means or the casing is eliminated and virtually no additional load imposed on the motor.

Another object is to provide such sealing means which will readily accommodate to the usual manufacturing variations in the clearance space between the movable blade and casing and in the interior dimensions of the adjacent end of the casing.

Further objects are to provide such sealing means which may be inexpensively fabricated and installed and which may be readily replaced by an inexperienced person without the use of tools.

Other objects and advantages of the invention will become apparent from the ensuing description which, taken together with the accompanying drawing, discloses a preferred mode of embodying the principles of the invention in practice.

In thisdrawing:

FIG. 1 is a perspective view of a common form of electrically-driven hair clipper to which the invention improvement may be adapted;

FIG. 2 is a detail, partly in section, to illustrate the invention as so adapted;

FIG. 3 is a detail in perspective to show the sealing means in its relation to the movable clipper blade and the driving end of the anmature;

FIG. 4 is a rear view of the movable blade and sealing means;

FIG. 5 is a side view thereof;

ice

'FIG. 6 is a transverse cross-section through the upper portion of the casing of the clipper showing the sealing means engaged, in part, Within the interior of the casing; and

FIG. 7 is a view similar to FIG. 5, showing an alternative form of sealing means.

Broadly regarded, the invention finds one important field of application in a common type of electricallydriven hair clipper, wherein a casing designed to be comfortably accommodated in the hand encloses a motor, usually consisting of a coil arranged, when connected to a 60-cycle source, to drive an armature flexibly supported at one end in cantilever fashion, and to the free end of which the movable blade is connected. The casing usually comprises upper and lower parts joined by screws to facilitate access thereto, and the inexpensive molding of these parts as shells of plastic composition. To avoid complications in the molds and the attendant expense, that end of the upper half where the free end of the armature exists from the casing is simply open from wall to wall and, since the movable blade oscillates adjacent thereto a clearance space is provided. Accordingly, during use, the hair clippings and other foreign matter may find a path between such blade and the casing whereby to enter the interior of the latter. Inasmuch as such detritus, when accumulated to some degree aside from the requirement of cleanliness generally, may affect the operation of the moving parts and/ or their lubrication--in the case where the motor may be of the rotary type-and, additionally, tend to foul the switch, it is desirable to seal such clearance space. To seal such clearance space in an effective, inexpensive manner, the invention comprises the securement to the rear face of the movable blade of a pad of readily deformable material preferably of transverse extent larger than the corresponding extent of the adjacent open end of the casing and of such thickness that a pontion thereof intromits such open end. Since the pad is rendered readily deformable, as by the employment of a sponge rubber, the intromitting portion thereof may yield as the movable blade reciprocates, thereby preserving the obturating relation thereof notwithstanding such reciprocation. By appropriate selection of the material for the pad, the motor is subjected to virtually no additional load and, moreover, since the pad undergoes immeasurable rubbing contact, it has demonstrated on test a life far beyond that of prior arrangements intended for the same general purpose. Desirably, the pad is cemented to the blade in order that initial installation and replacement, when required, may be facilitated. It will be understood that the pad has an opening to clear the free end of the armature where it engages the .movable blade.

Reverting to the drawing, FIGS. 1 and 2, there is shown a conventional type of hair clipper comprising upper and lower casing portions 10 and 11 of shell-like form secured together by screws (not shown). The casing encloses a driving motor and a cantilever-mounted armature (not shown) to the distal end of which is aflixed a link in the form of a resilient arm 13 having two extensions 15-15 engaged in apertures 1616 in the movable blade 17. The central extension 18 bears on the blade intermediate its apertures 1616 and is arranged to bias the blade 17 into sliding contact with the fixed blade or comb 21. This latter is affixed to the lower part 11 of the casing by screws (not shown) in the usual manner.

In order that the movable blade 17 may oscillate transversely free of the adjacent end of the casing part 10, a clearance space 23 is provided between the forward end 24 of the part 10 and, unless sealing is provided, an entrance to the interior of the casing obtains. Accordingly, the invention comprises a seal in the form of a pad 31 .desirably cemented to the rear face 33 of the blade 17 (FIGS. 3, 4 and 5) having a periphery homologous with that of the opening 32 (FIG. 6); in this case trapezoidal. In its normal aspect, i.e., disassembled form, the pad has transverse dimensions exceeding those of the opening 32,.e.g., overlapping the opening by say on the top and sides or, if desired, on all four sides, and a thickness somewhat greater than the width of the clearance space 23. In practice, the raw material from which the pad is punched may have the adhesive already applied and protected and preserved by a cloth backing which,:wl1en stripped off at the time of application, exposes the live adhesive. Material of this character is commercially available.

The pad comprises a readily deformable elastomer such as a spongy natural or synthetic rubber, e.g., polyurethane, this latter being available in a grade having myriad disconnected porosities and therefore distinctly of a cushiony character, of extremely light weight and capable of being compressed and decompressed for an almost indefinite number of cycles without diminution in its compliance. Consequently, when the blade and pad are installed, a major portion of the pad is compressed into a plugging relation with the opening 32 of the casing whereby to provide an extremely resilient seal with respect thereto. As mentioned hereinabove, by initially providing the margin of the pad oversize, the act of compressing the same into the opening is assurance that the resilient nature of the material will be utilized to a degree assuring preservation of the sealing action.

One type of raw material found acceptable for the pad is a polyurethane foam which may be obtained commercially in sheets of suitable thickness and in almost any degree of compressive strength, possesses a high degree of tear strength and resistance to wear. Such material is not harmed by oil and will retain its resilience and flexibility over a range of from F. to 250 F. It can be readily die cut.

For use for the invention pad material having the following properties has been found quite suitable: Density: 1.8 to 2.2 pounds per cubic foot.

Compression Set: According to A.S.T.M. Specification D395-55, Method B at 50% deflection is 20% maximum.

Tensile Strength (without backing): 15 p.s.i. minimum.

Elongation (without backing): 200% minimum.

Tear Strength (without backing): According to AS. T.M. Specification D624-54T, Die C, 3 pounds per inch of width.

Adhesion: Mylar backing to steel, tested according to A.S.T.M. DlOOO-SS T. is 64 ounces per inch of width.

Odor: Imperceptible after sealing in air-tight container for 168 hours at 250 F.

It will be noted that the portion of the pad ,co-extensive with the clearance space provides one sealing surface extending across the edges of the casing defining the opening 32 and another sealing surface within the casing, thereby creating a more or less tortuous abutment which assures maximum realization of the sealing function.

By the use of material for the pad having a high degree of compliance, the reciprocation of the blade merely flexes the pad in a lateral direction without affecting its sealing function. Moreover, by selecting a material of light weight and easy deformability, the load on the driving motor presented by the pad is virtually undetectable.

Additionally, removal of the movable blade presents no problem since the material of the pad will readily accommodate relative to the adjacent portions of the casing by deforming as required and, upon replacement, the pad will adapt similarly, but in reverse fashion, i.e., with a substantial part of the thickness thereof in obturating relation with the opening in the casing, all without any special effort on the part of the mechanic.

As will be apparent, the pad is provided with an opening 41 to allow for passage of the arm 13.

An alternative embodiment of the pad is seen in FIG. 7 wherein the lower face 42 of the pad 31a is beveled to conform more accurately with the junction between the casing parts 1!) and 11, it being observed from FIG. 2 that such surface 44 is at an angle to the plane of the movable blade 17. However, due to the compression fit between the pad and opening 32 it has been found that the square face 45 (FIG. 5), taking into account oversized dimensions for all four sides of the pad, is adequate for all practical purposes and, moreover, a pad having square edge faces can be punched from sheet raw material by the use of simple dies.

The inventive concept is not to be regarded as limited to a pair of shearing blades, one of which is movable and the other fixed in the true sense, but is equally appicable to an arrangement wherein a pair of shearing blades are both movable in opposite directions. The second movable blade which confronts an opening at the adjacent end of the casing could likewise be equipped with the invention pad functioning in a manner similarly to that already described. Obviously, the arrangement will be such that no interference will occur between the two pads.

While I have shown particular embodiments of my invention, it will be understood, of course, that I do not wish to be limited thereto since many modifications may be made and I, therefore, contemplate by the appended claims to cover any such modifications as fall within the true spirit and scope of my invention.

1 claim:

1. A hair clipper comprising: a hollow casing enclosing a driving mechanism, one end of said casing having an upper part and a lower part, the upper part being open and said lower part extending beyond said open end of said upper part; a fixed shearing blade secured to said lower part and extending upwardly parallel to said open end to define a space therebetween, a movable shearing blade positioned in said space parallel to said fixed shearing blade and said open end and driven by a link extending from said driving mechanism, said mechanism being adapted to reciprocate said movable shearing blade in a direction parallel to said fixed shearing blade to provide a shearing function therewith, said movable blade being spaced from said open end to provide a clearance space therebetween; and means for sealing said clearance space comprising a readily compressible pad bonded to the side of said movable blade facing said open end for reciprocation therewith, said pad being of such thickmess that it extends beyond said clearance space, said pad being intromitted in said open end, said pad having such transverse dimensions in its decompressed state as to accommodate to the transverse dimensions of said open end with a resilient plugging fit, and said portion of said pad between said movable blade and said open end being laterally unconfined to permit ready flexing thereof with virtually no additional load being imposed on said driving mechanism.

.2. The combination in accordance with claim 1 further characterized in that the pad has an aperture for passage of the link. 7

3. The combination in accordance with claim 1 wherein said pad comprises an elastomer.

UNITED STATES PATENTS References (liked by the Examiner 2,171,888 9/1939 OConnor 30-43.92 3,105,298 10/1963 Carissirni 30-4392 FOREIGN PATENTS 825,518 12/1959 Great Britain.

WILLIAM FELDMAN, Primary Examiner.

J. C. PETERS, Assistant Examiner. 

1. A HAIR CLIPPER COMPRISING: A HOLLOW CASING ENCLOSING A DRIVING MECHANISM, ONE END OF SAID CASING HAVING AN UPPER PART AND A LOWER PART, THE UPPER PART BEING OPEN AND SAID LOWER PART EXTENDING BEYOND SAID OPEN END OF SAID UPPER PART; A FIXED SHEARING BLADE SECURED TO SAID LOWER PART AND EXTENDING UPWARDLY PARALLEL TO SAID OPEN END TO DEFINE A SPACE THEREBETWEEN, A MOVABLE SHEARING BLADE POSITIONED IN SAID SPACE PARALLEL TO SAID FIXED SHEARING BLADE AND SAID OPEN END AND DRIVEN BY A LINK EXTENDING FROM SAID DRIVING MECHANISM SAID MECHANISM BEING ADAPTED TO RECIPROCATE SAID MOVABLE SHEARING BLADE IN A DIRECTION PARALLEL TO SAID FIXED SHEARING BLADE TO PROVIDE A SHEARING FUNCTION THEREWITH, SAID MOVABLE BLADE BEING SPACED FROM SAID OPEN END TO PROVIDE A CLEARANCE SPACE THEREBETWEEN; AND MEANS FOR SEALING SAID CLEARANCE SPACE COMPRISING A READILY COMPRESSIBLE PAD BONDED TO THE SIDE OF SAID MOVABLE BLADE FACING SAID OPEN END FOR RECIPROCATION THEREWITH, SAID PAD BEING OF SUCH THICKNESS THAT IT EXTENDS BEYOND SAID CLEARANCE SPACE, SAID PAD BEING INTROMITTED IN SAID OPEN END, SAID PAD HAVING SUCH TRANSVERSE DIMENSIONS IN ITS DECOMPRESSED STATE AS TO ACCOMMODATE TO THE TRANSVERSE DIMENSIONS OF SAID OPEN END WITH A RESILIENT PLUGGING FIT, AND SAID PORTION OF SAID PAD BETWEEN SAID MOVABLE BLADE, AND SAID OPEN END BEING LATERALLY UNCONFINED TO PERMIT READY FLEXING THEREOF WITH VIRTUALLY NO ADDITIONAL LOAD BEING IMPOSED ON SAID DRIVING MECHANISM. 